Error when shadowing function name in PhantomJS

Consider the following code:

class Foo {
  bar(bar) {
    return bar;
  }
}

The transformed version will throw the following error in PhantomJS 2.1.1

SyntaxError: Cannot declare a parameter named 'bar' as it shadows the name of a strict mode function.

This issue is likely caused by a bug in WebKit also discussed here:

• https://github.com/babel/babel/issues/1456
• https://github.com/mishoo/UglifyJS2/issues/179

Working around this would likely require the parameter to be renamed.